Conventionally, a saddle support constructed as described above as disclosed in U.S. Pat. No. 3,992,054, comprises a support member having cylindrical upper and lower surfaces and a receiving member supported to the support member and having also a cylindrical lower surface, so that a bolt is used to support the saddle at the upper portion of the seat post in a manner permitting an adjustment in its dip and elevation, i.e., in vertical angles which are longitudinal of the bicycle.
The saddle inclination is adjusted with respect to the longitudinal center line of the bicycle frame by rotating the seat post with respect to a seat tube fixed to a bottom bracket of the bicycle frame.
Recently, attempts have been made to reduce the air resistance associated with a bicycle's running, and to this end the bicycle frame or seat post, especially of a racing bicycle, is formed in a streamlined shape in cross section to reduce the air resistance.
When the seat tube or the seat post connected thereto has a streamlined cross section, the seat post cannot be rotated with respect to the seat tube. Hence, the inclination of the saddle, is not adjustable with respect to the longitudinal center line of the bicycle frame. In other words, when the seat tube is fixed to the bottom bracket in a condition of being improper with respect to the longitudinal center line of the frame, the saddle cannot be adjusted to a proper position.